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  - CopyRight:	(C) dGB Beheer B.V.
  - Author:	R. K. Singh	
  - Date:	June 2007
  - Contents:	Tutorial Attribute	
  - RCS:	$Id$
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<body background="backg.png"><title>Tutorial Plugin : The Tutorial Attribute</title>
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<h1>Tutorial Attribute</h1>
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<a href=#intro>Intro</a>
<a href=#scale>Scale</a>
<a href=#square>Square</a>
<a href=#smooth>Smooth</a>

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<a name=#intro><h3>Intro</h3>

<p> Here, you can perform the same operations on seismic data as in the <b>Tut Seismic Tools</b>, but the output in this case is an attribute instead of another seismic cube. From the user point of view the biggest advantage is that you can apply this attribute on another attribute or alternatively, you can use this output attribute as input for another attribute. From the <b>OpendTect</b> menu, select <center><br><b>Processing  --> Attributes</b></center><br>Or click on the <b>Edit Attributes</b> icon in the toolbar to open the Attribute Editor dialog. From the drop-down list, select the <b>Tutorial</b> attribute. In the <b>Input Data</b> selection field, select an existing seismic cube or a pre-defined attribute. You can choose from three available operations in the <b>Action</b> field and accordingly specify the corresponding input parameters:<p>

<a name=#scale><h3>Scale</h3>

<p> It performs a linear scaling of the form <b>a + b * x</b>, where parameters <b>a</b> and <b>b</b> are taken from the inputs <b>Shift</b> and <b>Factor</b> respectively.<p>

<a name=#square><h3>Square</h3>

<p> As the name suggests, it takes the square of data values.<p>

<a name=#smooth><h3>Smooth</h3>

<p> Here, we have got two different types of smoothing: <b>Horizontal</b> and </b>Vertical</b>. 
<p> The </b>Vertical</b> smoothing takes samples above and below the data sample along the same trace and is similar to that in <b>Tut Seismic Tools</b> and produces the same results. You can choose a <b>Low</b> or <b>High</b> filter strength to specify whether 3 or 5 samples are taken for calculating the mean.
<p> The <b>Horizontal</b> smoothing involves computation using samples from the neighbouring traces. If you want the selection of samples to be guided by a steering cube, you can select one in the <b>Steering Data</b> field by choosing <b>Full</b> or <b>Central</b> option in the <b>Steering</b> field. A rectangle centred around the data sample is taken with the size of the rectangle specified by the <b>Stepout</b>. The output value is the arithmatic mean of all the values within this rectangle.<p>

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